A10 valves

[bsa-bill]

Lapped in the vales on A10 project last night, got a nice matt ring around
each about an 16th inch.
put the springs and collets on and filled the heads with diesel/petrol
mixture.
Checked it this morning, most of the liquid still there  -   maybe one pot
has dropped a sixth and a the other a quarter
slight moistness in one ex port and enough liquid that it can be seen in the
other.
Now my question is - is this acceptable or should there be no leakage at
all, they were left for about twelve hours and diesel/ petrol makes a good
penetrating oil.

All the best - Bill

[LJ.]

Well Bill... I'm no engineer or mechanic but it sounds good to me. Diesel or penetrating oil will get through as thats what the stuffs designed to do. I'd be happy with your results.

Incidently I had my valves done by SRM, very happy with what they done. Boy! you could feel the compression afterwards when the head was refitted.

As some BSA friends have said to me... These old bikes are very forgiving! and I think it is very true!

[bsa-bill]

Well I hope so Erling, save me getting the valve compressor out again 8)

[dpaddock]

Perhaps good enough for roadwork, but . . .
For competition, I do the following:
   Lap the valves, diluting the paste with light oil after every twenty or so rotations.
   Wipe the surfaces with facial tissue until they're clean.
   Drop the valves in and fill the chambers with rubbing alcohol. Do NOT fit the springs or oil the faces.
   Wait a few minutes.
   Check the ports for wetness.
   Repeat the process if leakage shows.
If you can't get a good seal this way, you might have a bent valve stem or an off-center valve guide. Stop and fix the problem.
Remember, the purpose of the valve spring is to follow the cam at all engine speeds: it's not there to seal the valves. That's your job.

[a10 gf]

Remember, the purpose of the valve spring is to follow the cam at all engine speeds: it's not there to seal the valves. That's your job.

Never tought of it that way, excellent!

Regards
E.

[bsa-bill]

Well almost finished our busy spell ( overtime working ) so will have more time shortly, so I have started to give this method a go. no intention of competion work but when the heads off might as well go for the best result I can, let you all know how it goes.
Then I have a spitfire camshaft to fit, so once again as the cases are to split might as well have the sludge trap cleaned ( oh joy )
we do have a compressor and air tools on the farm so I'm thinking there is an attachment like a large screwdriver bit, might be usefull for removing the caps --- ah getting ahead of myself .

all the best - Bill

[bsa-bill]

Well I used Dpaddocks method to grind in the vavles, did both sides although it needed two goes on the troublesome side to get it them to seal.
used thin fork oil ( it was at hand ), both sides showed no sign of leakage after several days - I'm happy
many thanks for all advise given

all the best - Bill

[a10 gf]

Hi Bill, about your (former) personal picture...  You own the cutaway A10 engine? Lucky you if so, any story about it? (start a new thread)

Regards
E.

[bsa-bill]

Hi Erling - no I don't own the engine just the picture, has not come out as well as I'd hoped ( hence the change )

All the best - Bill